Secondary immunologic consequences in chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

Clinical evidence suggests that patients with Chromosome 22q11.2 deletion (Ch22q11.2D) have an increased prevalence of atopic and autoimmune disease and this has been without explanation. We hypothesized that the increase in atopy was due to homeostatic proliferation of T cells leading to a Th2 skew. We performed intracellular cytokine staining to define Th1/Th2 phenotypes in toddlers (early homeostatic proliferation) and adults (post homeostatic proliferation) with this syndrome. To attempt to understand the predisposition to autoimmunity we performed immunophenotyping analyses to define Th17 cells and B cell subsets. Adult Ch22q11.2D patients had a higher percentage of IL-4+CD4+ T cells than controls. Th17 cells were no different in patients and controls. In addition, adult Ch22q11.2D syndrome patients had significantly lower switched memory B cells, suggesting a dysregulated B cell compartment. These studies demonstrate that the decrement in T cell production has secondary consequences in the immune system, which could mold the patients' clinical picture.

Immunodeficiencies

Primary immunodeficiencies (PIDs) are uncommon, chronic and severe disorders of the immune system in which patients cannot mount a sufficiently protective immune response, leading to an increased susceptibility to infections. The treatment of choice for PID patients with predominant antibody deficiency is intravenous immunoglobulin (Ig) replacement therapy. Despite major advances over the last 20 years in the molecular characterization of PIDs, many patients remain undiagnosed or are diagnosed too late, with severe consequences. Various strategies to ensure timely diagnosis of PIDs are in place, and novel approaches are being developed. In recent years, several patient registries have been established. Such registries shed light on the pathology and natural history of these varied disorders. Analyses of the registry data may also reveal which patients are likely to respond well to higher Ig infusion rates and may help to determine the optimal dosing of Ig products. Faster infusion rates may lead to improved convenience for patients and thus increase patient compliance, and may reduce nursing time and the need for hospital resources. Data from two recent studies suggest that Gamunex and Privigen are well tolerated at high infusion rates. Nevertheless, careful selection of patients for high infusion rates, based on co-morbid conditions and tolerance of the current infusion rate, is advisable. Based on the available data, intravenous Ig offers broad protection against encapsulated organisms. As vaccine trends change, careful monitoring of specific antibody levels in the general population, such as those against pneumococcal and meningococcal bacteria, should be implemented.

Applying an adaptive watershed to the tissue cell quantification during T-cell migration and embryonic development

Cell and particle quantification is one of the frequently used techniques in biology and clinical study. Variations of cell/particle population and/or protein expression level can provide information on many biological processes. In this chapter, we propose an image-based automatic quantification approach that can be applied to images from both fluorescence and electron microscopy. The algorithm uses local maxima to identify labelling targets and uses watershed segmentation to define their boundaries. The method is able to provide information on size, intensity centroids and average intensity within the labelling partitions. Further developed from this method, we demonstrated its applications in four different research projects, including recruitment enumeration of circulating T cell in non-lymphoid tissues, cell clustering in the early development of the chick embryo, gold particle localization and clustering in electron microscopy, and registration/co-localization of transcription factors in neural tube development of early chick embryo. The advantages and limitations of the method are also discussed.

The nature and predictors of stroke knowledge amongst at risk elderly persons in Brisbane, Australia

PURPOSE

The aim of the study was to investigate the nature, extent, and predictors of stroke knowledge amongst people at risk of stroke.

METHOD

A total of 273 questionnaires were distributed to three types of sites in metropolitan Brisbane (retirement villages, senior citizens and bowls clubs), and this strategy yielded a response rate of 37%. Of the surveys returned, 75 were retained in this study on the basis that: (a) participants met our criteria for being at risk of stroke (i.e., they reported one or more modifiable stroke risk factor, such as hypertension), and (b) they returned a completed Stroke Knowledge Test (SKT).

RESULTS

Descriptive analyses revealed the overall level of stroke knowledge in this group was fair (approximately 50% of SKT items answered correctly, on average). SKT performance trends showed that participants did not have misconceptions about stroke but that more than 50% of the sample did not know the answer to seven out of 20 SKT items. Some overlap was identified regarding the issues about which participants in this and other previously researched groups admit they lack knowledge, such as the extent of increased stroke risk associated with smoking; however, the number of knowledge gaps identified in this sample was almost double that reported previously amongst stroke survivors and the general community. Analyses undertaken to explore determinants of stroke knowledge revealed age and education but not risk factor variables as significant predictors.

CONCLUSION

Overall, findings suggest that it is presently difficult to predict an individual's understanding of stroke and that there is a need to increase stroke education, especially if this can address issues that people at risk of stroke admit they do not understand.

Risky sexual behaviours of high-school pupils in an era of HIV and AIDS

OBJECTIVE

To identify risky sexual behaviours and demographic factors that place high-school pupils at risk of HIV and AIDS.

METHODS

A cross-sectional study was undertaken to explore factors influencing the sexual behaviour of high-school pupils (mean age 15.4 years; SD 1.11). Structured self-reported questionnaires were completed by all grade 10 pupils (N = 805) at all the Wentworth, Durban, public high schools.

RESULTS

Significant gender differences in sexual practices were reported, such as males being more likely to engage in sexual activity than females (OR 4.92; p < 0.001). More males (24.8%) initiated sex before age 12, compared with more females (30%) who initiated sex between 16 to 20 years of age (p < 0.001). Significantly more males preferred older partners than females (p = 0.002), more females were forced to have sex than males (p = 0.009), and more males used alcohol on the last occasion of sex than females (p = 0.04). Religious affiliation and parental supervision were found to have a significant effect on sexual activity among pupils.

CONCLUSIONS

High-school pupils are at high risk of HIV and AIDS, yet they continue to engage in risky sexual behaviours. Preventive efforts therefore need to be aggressively up-scaled and redirected towards specific risky practices, taking gender differences into account. Contextual factors such as religious norms and parental supervision also require greater attention. Risky sexual behaviours are reflective of a broader crisis in society.

CASP8 variants D302H and -652 6N ins/del do not influence the risk of colorectal cancer in the United Kingdom population

Polymorphisms in CASP8 at 2q33.1 have been associated with the risk of developing cancer, specifically, the D302H variant (rs1045485) with breast cancer in the European population and the −652 6N ins/del promoter variant (rs3834129) with multiple tumours including colorectal cancer (CRC) in the Chinese population. We evaluated the relationship between −652 6N ins/del and D302H variants and risk of developing CRC in the UK population by genotyping 4016 cases and 3749 controls. Both variants showed no evidence of an association with risk of developing CRC (P=0.42 and 0.22, respectively). In contrast, the recently identified CRC susceptibility allele rs6983267 mapping to 8q24 was significantly associated with disease risk (P=8.94 × 10⁻⁸). It is thus very unlikely that variation in CASP8 defined by −652 6N ins/del or D302H influences the risk of CRC in European populations. The implications of our findings both in terms of population-specific effects and publication bias are discussed.

A pilot investigation of effectiveness of a memory-improvement program on subjective and objective memory in healthy young adults: directions for future research

Previous research on the effectiveness of memory-improvement programs has typically included older adults or those with cognitive impairments. Results from these studies have been difficult to generalise to other populations and yielded inconsistent results, partly depending on the type of memory measured. Given that the effectiveness of memory-improvement programs on young healthy adults is not well understood, the aim of this study was to evaluate a commercially available memory training program, Memory Power, marketed as effective for all age groups, and all types of memory. Twenty, first-year psychology students were randomly allocated to one of two groups: Memory Power or Control. It was hypothesised that Memory Power participants would have significantly increased objective memory performance (RAVLT, RMBT), subjective memory functioning (EMQ, SMQ), and reported use of prospective memory aids (MAQ) at Follow-Up, than Controls. Multiple 2 x 2 mixed repeated-measures ANOVAs were used to assess training effects between Memory Power and Control groups, across Baseline and Follow-Up sessions. No significant group differences were found in subjective memory functioning, or reported use of prospective memory aids. Findings on objective memory function were mixed; no significant effects were found with the (RAVLT), but significant effects (a group main effect and a group by session interaction) were found using RMBT, suggesting improved performance on this measure of memory function for trained participants. The implications of these results for memory-improvement programs more broadly are discussed.

Intracellular autoantigens: diagnostic fingerprints but aetiological dilemmas

Autoimmune diseases such as systemic lupus erythematosus, scleroderma, Sjögren's syndrome, mixed connective tissue disease and dermato/polymyositis are each characterized by distinct sets of autoantigens and antibodies which confer on each disease a specific immune profile or fingerprint. These immune fingerprints have advanced our management of this group of diseases, as aids in differential diagnosis and earlier recognition. In lupus and scleroderma, multiple antigen/antibody systems characterize these fingerprints and the autoantigens appear to be located in separate cell compartments of the nucleus, nucleolus and cytoplasm. Because these antibodies are so distinctive for each disease, the response must be antigen driven or at least antigen directed. However, the apparent multi-focus location of the autoantigens poses a problem. It now appears that in scleroderma this dilemma may be explained by the consideration that at a certain time point in cell metabolism all the known autoantigens may be assembled at one location to form a single structural entity. It is possible that this assembly of antigens may be required for a specific cellular function. An autoimmune response to this transiently assembled structure comprising several different proteins and nucleic acids could result in the complex immune response seen in this disease.

Prognostic factors for survival after embolization of hepatic metastases in uveal melanoma

8562

Background: Liver is the most common site of metastasis (>80%) in patients with uveal melanoma. Embolization of the hepatic artery has been used to control hepatic metastases. Methods: Uveal melanoma patients with hepatic metastases embolized with iodized poppy seed oil and gelatin sponge, and either BCNU (chemoembolization, CE) or GM-CSF (immunoembolization, IE) during periods when each of these drugs was the agent of first choice, were evaluated. Prognostic factors that predict OS and progression free survival (PFS) in the liver (PFS-L) and in the extra-hepatic systemic organs (PFS-S) were analyzed univariately using the log-rank test and multivariately using Cox proportional hazards model. The following parameters were evaluated: age, gender, pre-existing extrahepatic metastases (EHM), LDH, AST, ALP, and treatment modality (CE or IE). Results: A total of 53 uveal melanoma patients with < 50% liver involvement with melanoma were analyzed. In comparison to the 19 patients (14 males/5 females) who underwent CE, the 34 patients who underwent IE (12 males/22 females) have significantly better OS (14.1 vs. 9.7 months, p=0.012) and PFS-S (10.2 vs. 4.8 months, P=0.013) in univariate analyses. Female patients outlived male patients (14.2 vs. 9.7 months, p=0.005). In Cox model, the shorter OS was associated with male gender (hazard ratio (HR)=2.1; 95% CI, 1.1–4.0; p=0.020), and marginally related to EHM (HR=1.8; 95% CI, 1.0–3.4; p=0.052). Independent predictors of shorter PFS-S included older age (HR=1.04 per year; 95% CI: 1.01–1.06; p=0.007), EHM (HR=2.1; 95% CI, 1.1–3.8; p=0.017), and CE (HR=2.1; 95% CI, 1.2–3.8; p=0.012). The gender-by-treatment interaction was also considered in all Cox models, but it was not significant. None of the covariates was a predictor of PFS-L in univariate or multivariate analyses. Conclusions: IE and female gender were found to be positive prognostic factors for survival after embolization of hepatic metastases.

No significant financial relationships to disclose.

Breast radiation dose estimates compared to measured doses from involved field radiotherapy (IFRT) or mantle fields for early stage Hodgkin lymphoma (ESHL)

18503

Background Breast cancer risk after mantle irradiation has prompted concern regarding the use of IFRT for ESHL. As breast cancer risk is radiation dose related, reliable estimates of breast radiation dose from IFRT might aid individual patient risk assessment. However, estimates of breast dose from radiation scatter/leakage beyond the involved field, using standard computer algorithms, are of uncertain accuracy. The aims of this study were to compare computer estimates with measured breast dose, and to compare breast dose from mantle and neck IFRT. Methods A phantom with breast tissue equivalent was used to determine breast dose using computerized treatment planning (CMS XiO), and to perform measurements within the phantom breast tissue using thermoluminescent dosimetry (TLD). These measurements were made for mantle fields and (neck) IFRT. Results Computer estimates and TLD measurements of breast dose in centigray (cGY) are shown for IFRT and mantle treatment, for a prescribed dose of 3000cGy, using 6MV X-rays from a Varian 21eX linear accelerator. Conclusions Breast dose from neck IFRT was lower than from mantle treatment by an order of magnitude, but being well outside the treatment field, was not accurately estimated by our computer algorithm. Work in progress will examine breast dose from mediastinal IFRT and involved node irradiation. Modifications to the planning algorithm may improve accuracy of dose estimates at a distance from the primary field, allowing routine breast dose estimates for patients. Ultimately, utilisation of dose-risk data may allow risk modelling and risk-benefit analysis of IFRT for ESHL in individual patients.

[Table: see text]

No significant financial relationships to disclose.